Electrical Engineering Stack Exchange
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Questions tagged [gsm]

GSM stands for Groupe Spécial Mobile. It is a standard set developed by the European Telecommunications Standards Institute (ETSI) to describe protocols for second generation (2G) digital cellular networks used by mobile phones.

GSM originally stood for Groupe Spécial Mobile, but since it went global, is often referred to as Global System for Mobile telecommunications. It is a standard set developed by the European Telecommunications Standards Institute (ETSI) to describe protocols for second generation (2G) digital cellular networks used by mobile phones.

Use this tag for questions related to any aspect of GSM systems.

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Confusion on GSM, GPRS, EDGE, 3G, 4G

I'm using a smartphone. When I turn off the cellular data or my mobile phone, I can still call and send SMS. Does that mean in this case the mobile using GSM? How can I know if it is GSM or GPRS? And which technique is used TDMA or CDMA? When I turn…
user16307
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Why is GSM interference audible?

We have all heard the buzzing sound that your speakers makes when you use your phone near your radio or amp. My question is why does one hear this interference if GSM operates at ~800-900MHz which is 40x higher than the highest humanly audible…
Keagan Ladds
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Why GSM module connects with same apn for different operator?

I'm using SIM868 in one of the GPS tracker that is being developed. HTTP protocol is used in sending data to the server.I have tried this with SIM cards of 2 network operations,Vodafone and Airtel. AT+SAPBR=3,1,"APN","www" is the command I use to…
Arun Joe Cheriyan
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GSM regulations for 850/900 MHz band and 1800/1900MHz

I understand that GSM regulations establish that transmissions power for two bands must be as follows, -Class 4 (2 W @ 850/900 MHz) -Class 1 (1 W @ 1800/1900MHz) But I also know that lower the frequency higher the range for equal transmission…
Denis
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Training sequence in a GSM frame?

I was reading about the GSM frames used in GSM communication. One thing pretty unusual caught my eye. Training Sequence: This is used by the receiver’s equalizer as it estimates the transfer characteristic of the physical path between the BTS and…
Kristof Tak
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Why does GSM allocate 200kHz data bandwidth for each mobile phone?

I read that the human range is commonly given as 20Hz to 20,000 Hz. But GSM channels are carrier frequencies of 200 kHz bandwidth. Is that because of SMS part? It seems for voice 20kHz must be enough. Why 200kHz?
user16307
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SIM808 not supporting SSL related commands

I am using SIM808 module. It's working fine with normal MQTT over TCP. But it's not working while implementing secured MQTT. I am sending this command (AT+SSLSETROOT="C:\USER\HENRY_SSL.CRT")to set the root certificate (referred this document"SIM800…
mohamed ali
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sim 800c doesn't get registered in network

I am using sim800c gsm module. It is showing some weird problems that am not able to figure out. The at commands are working fine. The problem is that, the module stops working after inserting the sim card. After the power button is pressed, it…
Mukesh
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What is the problem with the GSM 590e module?

I have a M590e GSM module (assembled from a kit) it is this kit in this link http://www.laser-shop.eu/arduino-platform/1277-arduino-gsm-gprs-module-m590e-900m-1800m-kit-1460408201.html I have sucessfully interfaced he module a PC and it does…
Pete
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sim800 restarts on battery but works fine on power supply

I am using SIM800L with PIC18F66J94 , but issue is that SIM800L keeps on restarting when powered by battery but works fine when powered by power supply . I have changed some battery to verify the issue but still sim800l restarts on battery .
Muhammad Ahmed
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GSM Power Control and Power Class

i know that the base station controls the power output of the mobile, keeping the GSM power level sufficient to maintain a good signal to noise ratio, while not too high to reduce interference, overloading, and also to preserve the battery life. now…
Kaden Ving
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Location of modulation and multiplexing in a GSM network

My question is regarding the location of GSM channel access methods TDMA/FDMA. Here is an illustration how voice is processed before reaching the base station on a tower: It is not mentioning the multiplexing(TDMA/FDMA) part. I have two…
user16307
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GSM layer 3 messages - System Information Type 2

I have 2 questions regarding the GSM standard, specifically about GSM layer 3 messages: How often the network sends "System Information Type 2" to the cellular phone ? Does "System Information Type 2ter" is replacing the "System Information Type…
AK87
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SIM908 POST Request

I want to send a couple of variables to a webpage in my server over the SIM908. Does anyone know how do send such data over POST protocol? I was able to complete the task using GET but currently nothing is working for POST.
Denis
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Signal of mobile network

Hi i want to have a circuit design for amplifying the mobile phone signal as at my place where i live the signal is very weak. or show me a site where it can help me please.
Satish
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